Gear testing apparatus



June 22, 1948. w. o. BENNETT, JR 2,444,016

GEAR TESTING APPARATUS Filed March 151, 1945 Patented June 22, 1948 GEAREESTING APPARATUS William Ogle Bennett, Jr., Lancaster Township, Iiancastcl: Gountygla., assignor to Hamilton Watch Companliancastenla.

Appligti'gnMarh 31, 1945, Seriali-No; 535149115 4j- Claims.

'Ems inventionrelates` to anA apparatus fon de the degree of! constancy ofi' said torque output With constant torque input and for. variouslanguz lar, positions ofrsaid gears:

Thetobject.offthewpresent invention is t-o-pro vide; anY apparatus by. means` of which. theA torque transfen between` two meshing `gears canl be measured.

A further object of the present: inventionfisi tio provide arrw apparatus through. which a constant torque may be applied to o rieof a pair of meshing gears anditheconstancy of' transfer of said torque determined during various angular increments of relative .gear toothposition-s.

A further object of` the present invention is to provide a constant torque on one of a pair of meshing' gears and a variablegresistancefon, the other f' Seid meshing sears,withvmeansto:measm ure the necessary variationin said. resistance to balance the torque transferred 'from said constant; torque source to` thereby measure the variation in torque caused'` by. theretatitm:V eff the gears todifferent. meshingipositions. t

A. still further object.,ofthepresent invention is to provide a rotatable support carrying one of a pair of meshed gears having a constant torque applied thereto and to rotate said support so that the center of said gear rotates about the center of the other of said pair of meshedgears and to provide means for measuring the constancy oi torque transfer between said gears.

A still further object of the present invention is to provide a simple means for balancing the torque transfer through a pair of mashed gears and indicating means showing the moment of force required to balance said torque.

With the foregoing and other objects in View, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein described may be made Within the scope of what is claimed Without departing from the spirit of the invention.

The invention is illustrated in the accompany ing drawing in which:

Fig. 1 is a broken perspective View of the torque measuring apparatus.

Fig. 2 is a. detailedvvievv of the indicating pointer.

The apparatus as conventionally7 illustrated shows a base l, having u'pstanding vertical Walls 2, 3 and 4 and a cut out portion 5. Journaled in the upstanding Walls 2 and 3 is a shaft 6 carrying a. support ii comprising, asirm'it; and; rear disc it andi S1 connectediby rods manda Izl The frontxdisc: carries4 ascaie indication* Vif adapted tofbe read againstanaindex pointer# 13@ carricdion the upstandingfwai-l Si., Secuindato, the baclixdisc Q-.is-,a circuiaupliate I5 whichiiscanried, concentric with;said;baoledisc;

: plat-e t t5; is secured to the: disc: ti by nuts; (notvshown: threaded omthea'bazoki oi; rods ttf and i i3 which; are, formed; with', shoulders abutting t the` plate; ieandmeduced nortionsiwhichinass through it;` and: t to receive: thefsecurinef nuts.` The rods' i6 and ii support a bridge i8 which saryesfasa bearing.,fonthenshaft;tacarryinemnacithesmcsa inggeaicsa` The, 1 shaft; Hilf also`y carries-a drum 2th om which. isyound. arcabie 22, carryinsfa weight aumenten 2:3, adapted? to 1 receiuc.` af number off weights 2t; to produce a: constant; forcefiat the. cincilmf'cnence ofthe drum, which force isstransmittedztlmoush the drum- Zishaft, iii'` to: producer.l attorqua gear Zavfhioh iisiin meshwithpgeahl;

' mountedcnashaftsi Whchisicure inacircuiar plate ltfaud @ook 2t whchis mountedcmandcarriediby saidinlata-i 5.2, Shanna is. mounted `centrally4 oi` circuiti@` plat? 155s and carriesl an.indexing-hand ,218: l Siecluedto ,illsenbof the shaft 25 is a measuring spring 3! which is shown here in the form of a helical spring secured at one end to the shaft 26 and at the other to a plate 3i.

The plate 3i is mounted on shaft 32 aligned With shafts 6 and 25 journalled in upstanding Wall i and terminating in a large circular disc 33 having a graduated scale 34 on one face thereof. Scale 34 is adapted to be read with a torque index pointer 35 carried on the upstanding wall 4. Also secured to the upstanding Wall is an arm 3B having an index rod 31 extending at right angles therefrom. The rod 3'! is cut away at its outermost end to form a V-shaped groove 38 (cross section of the rod) Which receives the indicating pointer 29, making it possible to easily observe when the torque on shaft 26 is balanced by the tension in spring 30.

In the operation of the testing device the pair of gears to be tested is mounted in the position of gears 20 and 25, the weights hung on the support 23 and the resulting torque on shaft 26 balanced by tensioning the spring 30. This tensioning is done by turning disc 33, shaft 32 and plate 3l until balance is indicated by pointer 29 in conjunction with the index rod 31. A reading on gear position scale l2 and torque scale 34 is taken. The support 1 is then rotated on its shaft 6 turning the gear 20 in mesh with the gear 25 a small rotational increment about said gear 25. Any change in the torque transfer can be easily noted by observing the hand 29 and its relative position in the V-shaped groove 38 of the index rod 37. Should there have been any change in the position of the hand 29 this change is balanced by increasing or decreasing the tension on the spring 30 and the reading of the scale 34 taken to correspond with the new reading of scale l2. By a series of such steps it is possible to determine the constancy of transfer of torque between the two gears for any relative position of contact of the teeth.

What is claimed is:

1. An apparatus for measuring torque transfer between a pair of meshing gears comprising a gear supporting member mounted for rotation about an axis, a plate carried by said member and secured to one end thereof, a shaft mounted coaxially with said axis, a second shaft, means journaling said second shaft coaxially with said plate mounted shaft, a measuring spring member connecting said shafts, a bridge carried by said plate and parallel thereto, means for mounting one of said gears to be tested between said bridge and said plate, said plate mounted shaft carrying the second gear of said meshing gears to be tested, means for exerting a constant torque on said first mentioned gear, and means for indicating a balance of torque between said plate mounted shaft carrying said second gear and said second shaft.

2. An apparatus for measuring torque transfer between a pair of meshing gears comprising a gear supporting member mounted for rotation about an axis, a plate carried by said member and secured to one end thereof, a shaft mounted coaxially with said axis, a second shaft, means journaling said second shaft coaxially with said plate mounted shaft, a measuring spring member connecting said shafts, a bridge carried by said plate and parallel thereto, means for mounting one of said gears to be tested between said bridge and said lplate, said plate mounted shaft carrying the second gear of the pair of meshing gears to be tested, means for exerting a constant torque on said first mentioned gear, means for indicating a balance of torque between said plate mounted shaft carrying said second gear and said second shaft, and a graduated disc carried by said second shaft for indicating the amount of said torque applied by said spring,

3.1An apparatus for measuring torque transfer between a pair of meshingl gears comprising a gear supporting member mounted for rotation about an axis, a plate carried by said member and secured to one end thereof, a shaft mounted coaxially with said axis and in said plate, a second shaft, means journaling said second shaft coaxially with said .plate mounted shaft, a coiled spring member connecting said shafts, a gear mounted for rotation on said plate, a second gear in mesh with said first gear and carried by said plate mounted shaft, means for exerting a constant torque on said first mentioned gear, an indicating balance finger mounted on said plate carried shaft to indicate balance of torque on said shaft and means for turning said second shaft and said connected coil spring to balance the torque on said plate carried shaft and bring the balance indicator to neutral position.

4. An apparatus for measuring torque transfer as claimed in claim 3, including a graduated disc attached to said second shaft, said disc carrying a scale for indicating the amount of said torque necessary to bring the torque balance indicator to neutral position.

WILLIAM OGLE BENNETT, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,352,906 Lyons July 4, 1944 FOREIGN PATENTS Number Country Date '96,334 Germany Feb. 25, 1898 314,925 Germany Oct. 18, 1919 675,150 Germany Apr. 29, 1939 

